Multicolor paints are used to coat surfaces where it is desirable for more that one color to appear in the coating. Generally there is a prominent color with speckles, streaks, or blotches of one or more additional colors dispersed therein. A wallpaper like appearance can be created by the utilization of multicolor paints. However, multicolor paints can be applied to many substrates where it would not be possible or practical to put wallpaper. For instance multicolor paints can be easily applied irregular surfaces and can be utilized in exterior applications. In fact, multicolor paints offer significant advantages as coatings for rough surfaces. Multicolor paints can also normally be applied at a lower cost than wallpaper.
Multicolor paints are widely used by professional painters in commercial and industrial settings. For example, multicolor paints are currently being used on a significant scale in painting commercial and public buildings, stadiums, and arenas. Multicolor paints can additionally be employed in painting vehicles, equipment, bridges, signs, and other types of structures. However, multicolor paints are not currently being employed to a significant extent by do-it-yourself painters. Since home owners often paint their own homes, multicolor paints are not widely used in painting private homes. Nevertheless, there is a large potential for utilizing multicolor paints in interior and exterior household applications.
Today most multicolor paints function on the basis of water/solvent incompatibility. This incompatibility keeps the different colors separated, thus creating a multicolor system with one application of the paint. Such multicolor paint formulations of necessity contain one or more organic solvents. A serious disadvantage of organic solvents is that they can be toxic, flammable and environmental pollutants. With the current escalation of environmental concerns, there is a need to reduce or eliminate the amount of organic solvents employed in paint formulations.
U.S. Pat. No. 4,968,741 and U.S. Pat. No. 5,122,566 disclose a latex which can be employed in manufacturing water reducible paints and paints made therewith which contain relatively small amounts of organic solvents, such as ethylene glycol n-butyl ether. U.S. Pat. No. 4,968,741 and U.S. Pat. No. 5,122,566 further disclose a process for producing a neutralized latex that is useful in the manufacture of water reducible coatings which comprises: (1) free radical aqueous emulsion polymerizing at a pH of less than about 3.5 a monomer mixture which comprises, based on 100 weight percent monomers: (a) from about 45 to about 85 weight percent vinyl aromatic monomers, (b) from about 15 to about 50 weight percent of at least one alkyl acrylate monomer, and (c) from about 1 to about 6 weight percent of at least one unsaturated carbonyl compound; in the presence of about 0.5 to 4.0 phm at least one phosphate ester surfactant and in the presence of about 0.5 to 4.0 phm of at least one water insoluble nonionic surface active agent to produce a latex; and (2) neutralizing the latex with ammonia to a pH which is within the range of about 7 to about 10.5 to produce the neutralized latex.